Error establishing a database connection

A few days ago I installed WordPress successfully and proceeded to add a post to my blog. It was all working fine until last night. Today when I checked my blog it said that there were no posts found and when I attempted to log in to the admin section I was told my username did not exist.

Having only put up one post I decided I would start over so I deleted the blog and reinstalled it, only to be met with this when I attempt to log in http://angelarmogida.com/blog/wp-admin or this when I try to view my blog: http://angelarmogida.com/blog

I can’t see there being any problems with my host since http://angelarmogida.com and other subdomains are working fine.

Any ideas?